Process and apparatus for generating and discharging foam



169-44. OR 2,968,334 8R Oct. 13, 1959 J. J. DUGGAN ETA]. 2,908,334

PROCESS AND APPARATUS FOR GENERATING AND DISCHARGING FOAM Filed March 14, 1957 2 Sheets-Sheet 1.

44 37 42 flag]. if; W 42 45 ZfKg; 37 Z! II I lNVE/VTORS JAMES J.DUGGAN ELIAS W.HA|N GEORGE C.HAET [|NGER Oct. 13, 1959 .1. J. DUGGAN El'AL 2,908,334

PROCESS AND APPARATUS FOR GENERATING AND DISCHARGING FOAM 2 Sheets-Sheet 2 Filed March 14, 1957 R a m m 0 N T M T E E VGN N M C S ESR Mmm M MEG a w fl fl L ATTOR United States Patent PROCESS AND APPARATUS FOR GENERATING AND DISCHARGING FOAM James J. Dnggan and Elias W. Hain, Charleston, W. Va., and George C. Haettinger, Indianapolis, Ind., assignors to Union Carbide Corporation, a corporation of New York Application March 14, 1957, Serial No. 645,965

27 Claims. (Cl. 169-32) This invention relates to novel process and apparatus for generating and discharging foam, by way of example, for extinguishing fires, shampooing human hair and rugs, as well as for shaving purposes.

An ideal foam generation and discharge system should be lightweight and small in size for easy storage and handling, simple to operate, and low in initial cost. Furthermore, the system should be relatively simple from the mechanical standpoint to minimize maintenance expenses.

An object of this invention is to provide a foam generating and discharging system meeting these requirements.

Another object of this invention is to provide a process and apparatus for providing foam from a foam generating solution and a propellant present in both the liquid and gaseous phases, the propellant being substantially immiscible with and of greater density than the foam generating solution.

Still another object of the present invention is to provide a simple combination foam generating-liquid level indicating device.

In the present invention, a foam generating solution and a propellant are charged into a container, the propellant being present in both the liquid and gaseous phases, as well as being substantially immiscible with and of greater density than the foam generating solution. Valve means and an eductor tube are provided in the container for discharging the foam, and in one embodiment of the invention a foam generator slideably mounted to the eductor tube floats between the immiscible liquids. Indicator means associated with the movement of the foam generator along said eductor tube permit visual determination of the propellant liquid level. The floating foam generator has a chamber communicating with the eductor tube for passage of foam therethrough. Orifices are located in the generator walls to meter the foam generating solution and the propellant into this chamber at proportional rates suflicient to generate the foam. The foam generating solution orifices are preferably positioned substantially oposite each other and slightly above the propellant orifice to provide maximum mixing turbulence in the chamber.

To generate foam in the container, the valve is opened and a pressure differential is established between the inside and the outside of the eductor tube. The floating foam generator then rises against the eductor tube bottom and provides a seal preventing passage of the solu tions into the chamber except through the orifices. Preferably the foam generator has a baflle section serving to prevent passage of the propellant through the foam solution orifices. The two liquids are then forced through their respective orifices by the propellant gas phase pressure, and the foam is generated in the previously mentioned chamber. Finally, the foam is discharged through the eductor tube and valve by the propellant.

Instead of movable indicator means, a sight gage containing an indicator ball may be positioned in the container wall for determining the liquid level of the prop 1 CC pellant. In this case, the foam generator is rigidly fastened to the bottom of the eductor tube.

The invention will be further described as particularly embodied in a process and apparatus for generating and discharging fire extinguishing foam but it is to be understood that the principles of the invention are also applicable to the generation and discharge of other foams, for example, foams suitable for shampooing and shaving.

In the accompanying drawings,

Fig. 1 is a sectional view in elevation of a fire extinguisher embodying one form of the present invention;

Fig. 2 is a fragmentary sectional view in elevation on an enlarged scale of the filling and discharging valve assembly of the fire extinguisher illustrated in Fig. 1;

Fig. 3 is a sectional view in elevation on an enlarged scale of the combination foam generating-movable propellant level assembly of the same fire extinguisher;

Fig. 4 is a view in elevation on an enlarged scale of the sight glass assembly used with the movable liquid level assembly of Fig. 3 to determine when the fire extinguisher has been filled to the proper level;

Fig. 5 is a view in elevation on an enlarged scale with parts broken away of an alternate propellant liquid level assembly comprising a sight gage containing an indicator ball; and

Fig.6 is a schematic sectional view in elevation of a fire extinguisher similar to that illustrated in Fig. 1, but embodying another form of the invention.

Referring now to the figures, the fire extinguisher 11 includes a casing 12 leak tightly sealed at either end to upper header 13 and lower header 14, all materials being impervious to or protected from the fluids stored therein. The lower end of casing 12 is rolled to form stiffening ring-base 15, and indicating means such as a suitable lateral head 16 is located at the proper longitudinal level around the inner wall of casing 12 to provide a visual means of determining the proper filling level for the foam generating solution.

In an opening 19, in the upper header, a collar 17 has a center annulus 18 for insertion of the eductor tube and foam generator assembly into the fire extinguisher. This assembly is positioned in the center annulus 18 by upper flange 20 and lower flange 21, the former being leak tightly attached to collar 17 by, for example, a threaded connection. An O-ring 22 positioned on shoulder 23 of collar 17 insures the maintenance of the seal. The upper end of eductor tube 24 fits inside and is metal bonded to lower flange 21, and the latter is thread-connected to the lower end of upper flange 20.

A filling and discharge valve assembly located inside upper flange 20 includes stem 25, the lower portion of which comprises beveledplug section 26 which seats on inwardly beveled shoulder 27 of center boring 28 and is limited in the open position by compression of coil spring 29 (see Fig. 2). The upper end of stem 25 extends into cavity 30 in the top part of upper flange 20, and is thread-connected to sight glass cap 31 which protrudes from the cavity 30. Coil spring 29 is positioned in compression between sight glass cap 31 and the bottom surface of cavity 30 to close the valve, and gasket 32 in recess 33 serves as a fluid seal between stem 25 and annular central passage 34 through upper flange 20, connecting center boring 28 and cavity 30. The components are sized to permit stem 25 to slide longitudinally in upper flange 20, and a substantial clearance is provided between the walls of cavity 30 and the moving components, sight glass cap 31 and coil spring 29. Indicating rod 35 inside eductor tube 24 extends upwardly through center passageway 36 of stem 25 into a recessed central part 37 of sight glass cap 31 protruding from cavity 30 when the extinguisher contains the proper amount of liquid propellant. The assembly is designed with sufficient clearance between indicating rod 35 and stem 25 for free movement of the rod. Trigger 38 in recess 39 of handle 40 swivels about pin 41 in the handle, and arm 42 of the trigger 38 contacts the top of sight glass cap 31. The handle 40 fits over cap 31 and the top of upper flange 20, and a hole 43 in the handle 40 permits visual inspection of the indicating rod tip 44 enclosed in the sight glass cap 31. The valve, normally in the closed position, is opened by pulling trigger 38 so that arm 42 presses downwardly on sight glass cap 31 which is thread-connected to valve stem 25. The coil spring 29 is further compressed and stem 25 is lowered, thus providing a space between the beveled plug section 26 and shoulder 27 of the upper flange 20 for fluid passage therethrough.

Center boring 28 of upper flange 20 communicates with conduit 45 which in turn is connected to discharge hose 46 by coupling 47. The fire extinguishing fluid is discharged through nozzle 48 which is sized in a manner well-known to those skilled in the art.

Eductor tube 24 with rod 35 therein extends into the lower header 14 where flexible prongs 49 attached at one end to the bottom of the indicating rod 35, are secured at their opposite ends to the bottom of the upper cylindrical part 50 of the floating foam generator 51 which is preferably a one-piece flexible polyethylene molding substantially unaffected by the stored fluids. The foam generator 51 is of a density such that the wide baffle 52 of the floating foam generator 51 lies at the propellantfoam generating solution interface when the extinguisher is fully charged before operation. The baflle 52 thus provides a means of separating the two liquids. The lower end of eductor tube 24 extends into the upper cylindrical part 50 of floating foam generator 51 and is stopped by shoulder 53. A loose fit is provided between tube 24 and the upper cylindrical part 50 to permit longitudinal sliding movement of the latter component along the outer surface of the eductor tube 24. This movement is limited by the length of slots 53a in the wall of upper cylindrical part 50, and pins 53b bonded to the outer wall of eductor tube 24 and extending through slots 53a. These pins 53b serve as a lower stop, and shoulder 53 provides an upper stop for longitudinal movement of floating foam generator. Any desired number of orifices 54, for example, four, are located at equal. intervals around the periphery of upper cylindrical part 50 and below shoulder 53 to provide communicating means between the foam generating solution in casing 12, and the foam generating chamber 55. The orifices 54 are preferably oppositely positioned from each other so that foam generating solution passing through any given orifice flows directly into the like solution emerging through an orifice on the opposite side of the floating foam generator 51. This arrangement has been found to provide maximum turbulence in the foam generating chamber 55 which in turn improves the fire extinguishing characteristics of the foam. A wire mesh screen 56 extends around the base of the upper cylindrical part 50 to prevent passage of solid particles and plugging of the orifices 54 thereby. The screen 56 is attached to upper cylindrical part 50 and wide baflle 52 for rigidity.

Orifice 57 in the center of bafile 52 provides a communicating means between the liquid propellant beneath the baflle 52 and the foam generating chamber 55, the propellant vaporizing and mixing with turbulent foam generating solution therein to form the desired fire extinguishing foam. The liquid propellant in the lower header 14 rises into the center passageway 58 of the lower cylindrical portion 59 and passes through wiremesh screen 60 to orifice 57, the screen preventing passage of solid particles which would plug the orifice.

The choice and proportion of constituents from which to generate and discharge fire-extinguishing foam by the process and apparatus of the present invention, is partially dependent on the type of fire to be extinguished. However, all suitable foam-generating solutions must have high foaming quality.

While there are undoubtedly many solutions that would be acceptable, a 1 to 5 weight percent solution of Unox in water has been found to be particularly suitable. Unox (sodium alkyl sulfate) is a commercially available foaming agent especially compounded for fighting fires.

The acceptable propellants have the following characteristics:

A large number of the halogenated hydrocarbons meet these requirements, e.g. dichlorodifluoromethane, bromotrifluoromethane, and chlorotrifluoromethane. Also, halogen-containing compounds are particularly suitable in this application because of their well-known fire inhibiting qualities. Freon-12 (dichlorodifluoromethane) is a particularly suitable propellant for the Unox-water solution, and has a liquid density of 1.28 grams per cubic centimeter at 70 F. The practical Freon composition range is approximately 3 to 12 percent of the total fluid weight, and the preferred range is 5 to 7 weight percent Freon12.

To charge the extinguisher, the valve and foam generator assembly is removed by unscrewing upper flange 20 from collar 17, the baffle 52 being sufliciently flexible for distortion and removal through the center annulus 18 without damage thereto. The casing 12 is then filled with water to the desired level, as visually determined by lateral bead 16. Next, the concentrated Unox foaming agent is poured into the extinguisher from a bottle or can which contains the required quantity to make the desired concentration, preferably 2 percent by weight. The valve and foam generator assembly is then reinstalled and the valve is screwed down tightly by hand, the O-ring 22' insuring a pressure-tight seal between collar 17 and upper flange 20. The extinguisher is shaken to mix and uniformly disperse the Unox throughout the water.

Discharge hose 46 is removed and a charging vessel containing liquid Freon-12 is attached to conduit 45. This vessel is sufficiently pressurized with a non-reactive gas, for example, air or nitrogen, to insure Freon flow into the extinguisher. The Freon is transferred by opening the extinguisher valve and the charging vessel dis charge valve. After transfer is complete, the valves are closed and the extinguisher is allowed to stand until the liquid Freon has settled to the bottom of the extinguisher and the gaseous Freon has risen through the water to the space above the liquid, in the top header 13. Suflicient Freon is charged into the fire extinguisher so that when the liquid Freon has settled to the bottom, the baflle 52 rises to the Freon-water interface. Indicating rod 35, flexibly attached to floating foam generator 51, also rises so that its tip 44 is visible in sight glass cap 31, showing that the extinguisher is properly charged (see Figs. 1 and 2). The charging vessel is then removed, the hose 46 replaced, and the extinguisher is ready for service.

The extinguisher operates in the following manner: The trigger 38 is pulled to open the valve. When this occurs, the pressure inside the eductor tube 24' is reduced and a pressure differential is established between the eductor tube interior and the surrounding fire extinguisher casing 12. This pressure differential forces the floating foam generator 51 upwardly against the bottom of the eductor tube 24, as illustrated in Figs. 1 and 3, to provide a seal. The vapor pressure of Freon in the gas space above the water forces the water-Unox solution through orifices 54 and the liquid Freon through orifice 57 in non-flammable immiscible with the foam-generating solution boiling point of no higher than 32 F. at atmospheric pressure vapor pressure of at least 5 p.s.i.g. at 40 F.

low toxicity.

the correct proportions to generate foam with the desired characteristics. The bafile 52 of foam generator 51 prevents passage of liquid Freon through the water-Unox orifices 54. The generated foam is discharged through eductor tube 24, center boring 28, hose 46, and nozzle 48 to the atmosphere by means of the Freon propellant. The foam is believed to be generated by a combination of factors including rapid vaporization of the liquid Freon, the turbulence caused by oppositely positioning the water- Unox orifices 54 above the Freon orifice 57, and the foam flow through eductor tube 24 and hose 46, as well as the high foamability of the Unox solution.

The preferred orifice sizes depend on the fluids to be processed and the discharge rate as well as the desired foam characteristics. In any event, the combined orifice area must be no greater than that permitted for an adequate pressure differential between the inside and outside of the eductor tube 24 to seal the bottom of the tube. If the pressure difierential is inadequate for the maintenance of such a seal, the Freon, water-Unox mixing ratio could not be controlled and the resultant foam would lose its excellent fire extinguishing characteristics.

For the Freon-12, Unox-water system, it has been found that an optimum foam is generated when the relative sizes of the orifices are such that the volume of Freon-d2 (converted to vapor at normal temperature and pressure) metered is approximately ten times the volume of Unox-water solution metered (measured as unfoamed liquid volume). The orifices should be sized so that the flow results in a solution discharge rate of at least 0.10 gallon per sq. ft. per minute and preferably 0.25 gallon .per sq. ft. per minute on the largest gasoline fire for which a particular extinguisher is designed, e.g., 0.085 inch diameter for the four Unox-water orifices, and 0.040 inch diameter for the Freon-l2 orifice in a 1 /1 gallon extinguisher which is suitable for extinguishing 12 square feet of gasoline fire.

If desired, a flow restricting foam orifice 69 may be inserted in the eductor tube 24 at an intermediate position between the inlet and outlet ends of such tube. When the fire extinguisher is operated as previously described, the Freon propellant evaporates as it passes through the Freon orifice 57 since the greatest pressure drop occurs at this point and the eductor tube interior is at substantially atmospheric pressure. The insertion of foam orifice 69 downstream from the Freon orifice 57 transfers the point of greatest pressure drop to such foam orifice, and most of the liquid Freon propellant is evaporated on passing therethrough. The advantage of such an orifice is that a shorter hose 46 may be used. The shorter hose is possible because the remaining liquid propellant and the foam-generating solution 'have an opportunity to become intimately mixed prior to vaporization of the remaining liquid propellant at the point of greatest pressure drop. Although some foam is generated between the inlet end and the foam orifice, the majority of the foam is generated downstream of the orifice 69 in this embodiment of the invention.

Fig. illustrates an alternate means of determining the propellant liquid level comprising a sight gage assembly 61. This assembly includes a cylinder 62 which is leak tightly connected at its inner end to the lower header 14 so as to communicate with the liquid propellant in casing 12. A sight window 63 of transparent plastic or glass is sealed against the outer end of the cylinder 62 and is retained by cap 64 which is threadconnected to the cylinder. A pocket section 65 of sight window 63 holds indicator ball 66 which is free to move up and down, and floats at the Freon-Unox" solution interface. The falling of ball 66 to the bottom of pocket 65 indicates that additional Freon must be charged into the extinguisher for generation and discharge of optimum quality foam. An opening 67 in the casing 12 and a center annulus 68 in the cap 64 permit visual location 6 of the indicator ball 66 and determination of the propellant liquid level. When this assembly is used, the foam generator 51 is rigidly attached to the bottom of eductor tube 24 in the position shown in Fig. 3 so that the bafile 52 is properly fixed at the Freon-Unox solution interface when the extinguisher is fully charged.

Fig. 6 illustrates another fire extinguisher embodiment of the invention similar to Fig. 1, except that gaseous instead of liquid Freon is metered into the eductor tube and the foam is generated near the top of such tube instead of at the bottom. Also, a foam generating assembly is not required at the bottom of the eductor tube. It is also contemplated that the gas phase Freon orifice of Fig. 6 may be used in combination with the liquid phase Freon orifice, floating foam generator assembly of Fig. 1.

Referring more specifically to Fig. 6, the components which are similar to those shown in the other figures are designated by similar reference numerals. Liquid Freon and the Unox solution are charged into the container 11 as previously described. On opening the discharge valve, the Unox solution is forced through the orifices 154 in the wall of the eductor tube 24 and rises through such tube to the foam generating section 155 of the eductor tube. At this level the Unox solution turbulently mixes with gaseous Freon propellant passing through propellant orifice 157 in the gas space above the Unox solution. A high quality fire extinguishing foam is generated by such turbulent mixing, and the foam is discharged through the valve and hose 46. In this embodiment, the bottom end of eductor tube 24 is closed to prevent leakage of liquid Freon into such tube. Although not illustrated in Fig. 6, the sight gage assembly 61 of Fig. 5 may be used to determine the liquid level of the Freon propellant in the bottom of container 11.

What is claimed is:

1. In apparatus for generating and discharging fireextinguishing foam, the combination of a container for holding a foam generating solution consisting of water and a foaming agent, and a halogen-containing hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; orifice metering means for passing the foam generating solution and the gas phase propellant into the eductor tube at proportional rates sufficient to generate such foam; and means comprising a sight gage contain ing an indicator ball, such gage being positioned in the container wall for determining the liquid level of the propellant in said container.

2. In apparatus for generating and discharging foam, the combination of a container for holding a foam generating solution and a propellant present in both the liquid and gaseous phases, the propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; and orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates suflicient to generate said foam in said chamber.

3. In apparatus for generating and discharging fireextingu-ishing foam, the combination of a container for holding a foam generating solution and a halogen-com taining hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing hydrocarbon propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator attaohed to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; and orifices in the walls of the generator for metering the foam generating solution and the pro pellant into said chamber at proportional rates suflicient to generate said foam in said chamber.

4. In apparatus for generating and discharging fireextinguishing foam, the combination of a container for holding a foam generating solution consisting of water and a foaming agent, and a halogen-containing hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; and orifices in the generator walls for metering the foam generating solution and the propellant into said chamber at proportional rates suflicient to generate said foam in said chamber.

5. In apparatus for generating and discharging foam, the combination of a container for holding a foam generating solution and a propellant present in both the liquid and gaseous phases, the liquid phase propellant being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; and orifices in the generator walls for metering the foam generating solution and the propellant into said chamber at proportional rates sufficient to generate said foam in said chamber, the foam solution orifices being substantially oppositely positioned from each other to provide maximum mixing turbulence in the chamber.

6. In apparatus for generating and discharging fireextinguishing foam, the combination of a container for hold'ng a foam generating solution consisting of water and a foaming agent, and a halogen-containing hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in sad container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with the bottom of said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates sufiicient to generate said foam in said chamber, the foam solution orifices being substantially oppositely positioned from each other and above the propellant orifice to provide maximum mixing turbulence in the chamber; and a bafiiecomprising part of the foam generator and serving to prevent passage of the propellant through said foam solution orifices.

7. In apparatus for generating and discharging foam, the combination of a container for holding a foam generating solution and a propellant present in both the liquid and gaseous phases, the liquid phase propellant being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam;

a foam generator slideably mounted to said eductor tube and adapted to float between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates sufiicient to generate said foam in said chamber; and indicator means associated with the movement of the foam generator along said eductor tube for determining the liquid level of said propellant in said container.

8. In apparatus for generating and discharging fireextinguishing foam, the combination of a container for holding a foam generating solution and a halogen-containing hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing hydrocarbon propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator slideably mounted to said eductor tube and adapted to float between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates suflicient to generate said foam in said chamber; and indicator means associated with the movement of the foam generator along said eductor tube for determining the liquid level of said propellant in said container.

9. In apparatus for generating and discharging fire extinguishing foam, the combination of a container for holding a foam generating solution consisting of water and foaming agent, and a halogen-containing hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator slideably mounted to said eductor tube and adapted to float between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates sufiiicent to generate said foam in said chamber; and indicator means associated with the movement of the foam generator along said eductor tube for determining the liquid level of said propellant in said container.

10. In apparatus for generating and discharging foam, the combination of a container for holding a foam generating solution and a propellant present in both the liquid and gaseous phases, the propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator slideably mounted to said eductor tube and adapted to float between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates sufiicient to generate said foam in said chamber, the foam solution orifices being substantially oppositely positioned from each other to provide maximum mixing turbulence in the chamber; and indicator means associated with the movement of the foam generator along said eductor tube for determining the liquid level of said propellant in said container.

11. In apparatus for generating and discharging foam, the combination of a container for holding a foam generating solution and a propellant present in both the liquid and gaseous phases, the propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator slideably mounted to said eductor tube and adapted to float between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with the bottom of said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates sufiicient to generate said foam in said chamber; sealing means between the eductor tube bottom and the foam generator for preventing passage of the solutions into said chamber except through said orifices; and indicator means associated with the movement of the foam generator along said eductor tube for determining the liquid level of said propellant in said container.

12. In apparatus for generating and discharging fireextinguishing foam, the combination of a container for holding a foam generating solution consisting of water and a foaming agent, and a halogen-containing hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator slideably mounted in said eductor tube and adapted to float between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with the bottom of said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates sufi'icient to generate said foam in said chamber, the foam solution orifices being substantially oppositely positioned from each other to provide maximum mixing turbulence in the chamber; sealing means between the eductor tube bottom and the foam generator for preventing passage of the solutions into said chamber except through said orifices; a baflle comprising part of the foam generator and serving to prevent passage of the propellant through said foam solution orifices; and the indicator means associated with the movement of the foam generator along said eductor tube for determining the liquid level of said propellant in said container.

13. In apparatus for generating and discharging foam, the combination of a container for holding a foam generating solution and a propellant present in both the liquid and gaseous phases, the propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with the bottom of said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates sufficient to generate said foam in said chamber; and means comprising a sight gage in the container wall for determining the liquid level of said propellant in said container.

14. In apparatus for generating and discharging foam, the combination of a container for holding a foam generating solution and a propellant present in both the liquid and gaseous phases, the propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an' eductor tube in said container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with the bottom of said eductor tube for passage of foam therethrough; orfices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates sufiicient to generate said foam in said chamber; and means comprising a sight gage containing an indicator ball, such gage being positioned in the container wall for determining the liquid level of said propellant in said container.

15, In apparatus for generating and discharging fireextinguishing foam, the combination of a container for holding a foam generating solution and a halogen-containing hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing hydrocarbon propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates sufficient to generate said foam in said chamber; and means comprising a sight gage containing an indicator ball, such gage being positioned in the container wall for determining the liquid level of said propellant in said container.

16. In apparatus for generating and discharging fireextinguishingfoam, the combination of a container for holding a foam generating solution consisting of water and a foaming agent, and a halogen-containing hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; orifices in the generator walls for metering the foam generating solution and the propellant into said chamber at proportional rates sufficient to generate said foam in said chamber; and means comprising a sight gage containing an indicator ball, such gage being positioned in the container wall for determining the liquid level of said propellant in said container.

17. In apparatus for generating and discharging foam, the combination of a container for holding a foam generating solution and a propellant present in both the liquid and gaseous phases, the propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with said eductor tube for passage of foam therethrough; orifices in the generator walls for metering the foam generating solution and the propellant into said chamber at proportional rates sulficient to generate said foam in said chamber, the foam solution orifices being substantially oppositely positioned from each other to provide maximum mixing turbulence in the chamber; and means comprising a sight gage containing an indicator ball, such gage being positioned in the container wall for determining the liquid level of said propellant in said a container.

18. In apparatus for generating and discharging fireextinguishing foam, the combination of a container for holding a foam generating solution consisting of water 11 and a foaming agent, and a halogen-containing hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with the bottom of said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the propellant into said chamber at proportional rates sufficient to generate said foam in said chamber, the foam solution orifices being substantially oppositely positioned from each other and above the propellant orifice to provide maximum mixing turbulence in the chamber; a bafile comprising part of the foam generator and serving to prevent passage of the propellant through said foam solution orifices; and means comprising a sight gage containing an indicator ball, such gage being positioned in the container wall for determining the liquid level of said propellant in said container.

19. In apparatus for generating and discharging fireextinguishing foam, the combination of a container for holding a foam generating solution consisting; of water and a foaming agent, and a halogen-containing hydrocarbon propellant present in both the liquid and gaseous phases, the halogen-containing propellant liquid phase being substantially immiscible with and of greater density than the foam generating solution; valve means and an eductor tube in said container for discharging the foam; a foam generator attached to said eductor tube and located between the immiscible propellant and foam generating solutions, said foam generator having a chamber in open communication with the bottom of said eductor tube for passage of foam therethrough; orifices in the walls of the generator for metering the foam generating solution and the liquid propellant into said chamber at proportional rates sufficient to generate said foam in said chamber, the foam solution orifices being substantially oppositely positioned from each other and above the propellant orifice to provide maximum mixing turbulence in the chamber; a baflle comprising part of the foam generator and serving to prevent passage of the propellant through said foam solution orifices; at least one orifice positioned in the eductor tube at a point between the bottom and top of such tube so that the liquid propellant is vaporized on passing therethrough; and means comprising a sight gage containing an indicator ball; such gage being positioned in the container wall for determining the liquid level of said propellant in said container.

20. In a process for providing foam from a foam generating solution, the steps comprising providing and storing in a single container such solution and a halogen containing vaporizable hydrocarbon propellant in direct contact with said solution and present in both liquid and gas phases, the liquid phase propellant being substantially immiscible with and of greater density than the solution, said solution being stored as a liquid layer between the liquid and gas phases of the propellant; separately passing controlled portions of said solution and of the propellant into a foam generating chamber by action of the pressure of the gas phase propellant; generating a foam in such chamber by effecting turbulent mixing of the foam generating solution and the propellant; and discharging the generated foam from such chamber by action of the propellant.

21. In a process for providing foam from a foam generating solution, the steps comprising providing and storing in a single container such solution and a halogencontaining vaporizable hydrocarbon propellant in direct contact with said solution and present in both liquid and gas phases, the liquid phase propellant being substantially immiscible with and of greater density than the solution, said solution being stored as a liquid layer between the liquid and gas phase of the propellant; separately passing controlled portions of said solution and said liquid phase propellant into a foam generating chamber by action of the pressure of the gas phase propellant; generating a foam in such chamber by turbulently mixing the foam generating solution and the propellant; and discharging the generated foam from such chamber by action of the propellant.

22. In a process for providing foam from a foam generating solution consisting of water and a foaming agent, the steps comprising providing and storing in a single container such solution and a halogen-containing vaporizable hydrocarbon propellant in direct contact with said solution and present in both liquid and gas phases, the liquid phase propellant being substantially immiscible with and of greater density than the solution, said solution being stored as a liquid layer between the liquid and gas phases of the propellant; separately passing controlled portions of said solution and said liquid phase propellant into a foam generating chamber by action of the pressure of the gas phase propellant; generating a foam in such chamber by turbulently mixing the foam generating solution and the propellant; and discharging the generated foam from such chamber by action of the propellant.

23. In a process for providing foam from a foam generating solution consisting of water and a foaming agent, the steps comprising providing and storing in a. single container such solution and a halogen-containing vaporizable hydrocarbon propellant in direct contact with said solution and present in both liquid and gas phases, the vaporizable liquid phase propellant being substantially immiscible with and of greater density than the solution, said solution being stored as a liquid layer between the liquid and gas phases of the propellant; separately passing controlled portions of said solution and said vaporizable liquid phase propellant into a first mixing zone by action of the pressure of the gas phase halogen-containing propellant; intimately mixing such foam generating solution and vaporizable liquid phase propellant in the first zone and partially generating the foam; controllably passing the partially generated foam into a second foam-generating zone and vaporizing the propellant during such passage; generating the remainder of the foam in the second zone; and discharging the generated foam from the second zone by action of the propellant.

24. In apparatus for generating and discharging foam, the combination of a single container; a foam generating solution and a halogen-containing vaporizable hydrocarbon propellant present in both liquid and gas phases and stored in said single container in direct contact with each other prior to such foam generation and discharge, the liquid phase propellant being substantially immiscible with and of greater density than the solution which is stored as a liquid layer between the liquid and gas phases of the propellant; valve means and an eductor tube in said container for discharging the foam; and orifice metering means for separately passing the foam generating solution and the propellant into the eductor tube at proportional rates sufiicient to generate the foam.

25. Apparatus according to claim 24 for generating and discharging foam, in which said orifice metering means are provided for separately passing said foam generating solution and the liquid phase halogen-containing hydrocarbon propellant into the eductor tube.

26. Apparatus according to claim 24 for generating and discharging foam, in which said orifice metering means are provided for separately passing said foam generating solution and the gas phase halogen-containing hydrocarbon propellant into the eductor tube.

13 14 27. Apparatus according to claim 24 for generating References Cited in the file of this patent and discharging foam, in which said orifice metering means are provided for separately passing said foam UNITED STATES PATENTS generating solution as well as the gas phase and liquid 2,361,982 Urquhart Nov. 7, 1944 phase halogen-containing hydrocarbon propellant into 5 2,70 ,600 Allen Feb. 22, 1955 the eductor tube. 

